port-acorn32/46998: Enhancements/fixes to seeq8005 driver

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>Number:         46998
>Category:       port-acorn32
>Synopsis:       Enhancements/fixes to seeq8005 driver
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-acorn32-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Sep 23 12:15:00 +0000 2012
>Originator:     Robert Sprowson
>Release:        
>Organization:
Self
>Environment:
>Description:
See diffs for proposed patch, and rationale here. Can supply patch by email if 
the web form mangles it.

@@ -106,7 +106,12 @@
The TX buffer size is not a function of the SEEQ chip, it is an arbitrary 
driver threshold, so I've renamed the define accordingly and added a new one to 
specify how many buffers are used (in my port I allow multiple packets to be in 
flight at once, so have used #ifndef, such that the makefile can override).

@@ -225,12 +230,11 @@
Comment corrected, and make use of the above defines.

@@ -443,6 +447,7 @@
Missing delay(1) added, otherwise the 20,000 timeout loop is dependent on the 
speed of your processor. Matches ea_stoptx logic now.

@@ -145,7 +150,7 @@
@@ -832,7 +840,7 @@
@@ -864,7 +872,7 @@
@@ -876,7 +884,7 @@
@@ -1107,7 +1113,7 @@
Renamed eatxpacket in line with other ea_* functions.

@@ -604,6 +609,9 @@
The FIFO empty check does nothing if the previous mode was 'read', but is 
required before changing the BUFCODE (per 80C04 datasheet page 19, note [2]). 
Then the mode is set to write, so a second FIFO empty check is needed incase 
the previous mode was read. 

@@ -901,7 +909,7 @@
Treat m0 as a pointer not an integer.

@@ -968,20 +976,18 @@
Remove double write of the NULL packet header. Either do memset/ea_writebuf or 
two writes to SEEQ_BUFWIN, but not both.
The calculation of nextpacket (for hdr[]) assumes bufstart = 0, and puts the 
packet header pointing in the wrong place when it isn't.

@@ -1195,9 +1201,6 @@
The setting of CFG2_OUTPUT is done in ea_init(), so this is duplicated code.
>How-To-Repeat:

>Fix:
--- seeq8005_148.c      Mon Jun 11 00:01:56 2012
+++ seeq8005_new.c      Sun Sep 23 11:56:42 2012
@@ -106,7 +106,12 @@
 #define DPRINTF(f, x)
 #endif
 
-#define        SEEQ_TX_BUFFER_SIZE             0x800           /* (> 
ETHER_MAX_LEN) */
+#ifndef EA_TX_BUFFER_SIZE
+#define EA_TX_BUFFER_SIZE              0x800           /* (> ETHER_MAX_LEN) */
+#endif
+#ifndef EA_TX_BUFFER_COUNT
+#define EA_TX_BUFFER_COUNT             1               /* (> 0) */
+#endif
 
 #define SEEQ_READ16(sc, iot, ioh, reg)                                 \
        ((sc)->sc_flags & SF_8BIT ?                                     \
@@ -145,7 +150,7 @@
 static struct mbuf *ea_get(struct seeq8005_softc *, int, int, struct ifnet *);
 static void ea_txint(struct seeq8005_softc *);
 static void ea_rxint(struct seeq8005_softc *);
-static void eatxpacket(struct seeq8005_softc *);
+static void ea_txpacket(struct seeq8005_softc *);
 static int ea_writembuf(struct seeq8005_softc *, struct mbuf *, int);
 static void ea_mc_reset(struct seeq8005_softc *);
 static void ea_mc_reset_8004(struct seeq8005_softc *);
@@ -225,12 +230,11 @@
        /*
         * Set up tx and rx buffers.
         *
-        * We use approximately a quarter of the packet memory for TX
+        * We set aside EA_TX_BUFFER_SIZE * EA_TX_BUFFER_COUNT for TX
         * buffers and the rest for RX buffers
         */
-       /* sc->sc_tx_bufs = sc->sc_buffersize / SEEQ_TX_BUFFER_SIZE / 4; */
-       sc->sc_tx_bufs = 1;
-       sc->sc_tx_bufsize = sc->sc_tx_bufs * SEEQ_TX_BUFFER_SIZE;
+       sc->sc_tx_bufs = EA_TX_BUFFER_COUNT;
+       sc->sc_tx_bufsize = sc->sc_tx_bufs * EA_TX_BUFFER_SIZE;
        sc->sc_rx_bufsize = sc->sc_buffersize - sc->sc_tx_bufsize;
        sc->sc_enabled = 0;
 
@@ -443,6 +447,7 @@
        timeout = 20000;
        do {
                status = SEEQ_READ16(sc, iot, ioh, SEEQ_STATUS);
+               delay(1);
        } while ((status & SEEQ_STATUS_RX_ON) && --timeout > 0);
        if (timeout == 0)
                log(LOG_ERR, "%s: timeout waiting for rx termination\n",
@@ -604,6 +609,9 @@
                ea_select_buffer(sc, SEEQ_BUFCODE_LOCAL_MEM);
                SEEQ_WRITE16(sc, iot, ioh, SEEQ_COMMAND,
                    sc->sc_command | SEEQ_CMD_FIFO_WRITE);
+
+               ea_await_fifo_empty(sc);
+
                SEEQ_WRITE16(sc, iot, ioh, SEEQ_DMA_ADDR, addr);
        }
 
@@ -832,7 +840,7 @@
        SEEQ_WRITE16(sc, iot, ioh, SEEQ_COMMAND,
                          sc->sc_command | SEEQ_CMD_RX_ON);
 
-       /* TX_ON gets set by eatxpacket when there's something to transmit. */
+       /* TX_ON gets set by ea_txpacket when there's something to transmit. */
 
 
        /* Set flags appropriately. */
@@ -864,7 +872,7 @@
 
        /*
         * Don't do anything if output is active.  seeq8005intr() will call
-        * us (actually eatxpacket()) back when the card's ready for more
+        * us (actually ea_txpacket()) back when the card's ready for more
         * frames.
         */
        if (ifp->if_flags & IFF_OACTIVE)
@@ -876,7 +884,7 @@
 
        /* tx packets */
 
-       eatxpacket(sc);
+       ea_txpacket(sc);
        splx(s);
 }
 
@@ -888,7 +896,7 @@
  */
 
 static void
-eatxpacket(struct seeq8005_softc *sc)
+ea_txpacket(struct seeq8005_softc *sc)
 {
        bus_space_tag_t iot = sc->sc_iot;
        bus_space_handle_t ioh = sc->sc_ioh;
@@ -901,7 +909,7 @@
        IFQ_DEQUEUE(&ifp->if_snd, m0);
 
        /* If there's nothing to send, return. */
-       if (!m0) {
+       if (m0 == NULL) {
                ifp->if_flags &= ~IFF_OACTIVE;
                sc->sc_config2 |= SEEQ_CFG2_OUTPUT;
                SEEQ_WRITE16(sc, iot, ioh, SEEQ_CONFIG2, sc->sc_config2);
@@ -968,20 +976,18 @@
        /* Follow it with a NULL packet header */
        memset(hdr, 0, 4);
        ea_writebuf(sc, hdr, bufstart + 4 + len, 4);
-       SEEQ_WRITE16(sc, sc->sc_iot, sc->sc_ioh, SEEQ_BUFWIN, 0x0000);
-       SEEQ_WRITE16(sc, sc->sc_iot, sc->sc_ioh, SEEQ_BUFWIN, 0x0000);
 
        /* Ok we now have a packet len bytes long in our packet buffer */
        DPRINTF(SEEQ_DEBUG_TX, ("ea_writembuf: length=%d\n", len));
 
        /* Write the packet header */
-       nextpacket = len + 4;
+       nextpacket = bufstart + len + 4;
        hdr[0] = (nextpacket >> 8) & 0xff;
        hdr[1] = nextpacket & 0xff;
        hdr[2] = SEEQ_PKTCMD_TX | SEEQ_PKTCMD_DATA_FOLLOWS |
                SEEQ_TXCMD_XMIT_SUCCESS_INT | SEEQ_TXCMD_COLLISION_INT;
        hdr[3] = 0; /* Status byte -- will be updated by hardware. */
-       ea_writebuf(sc, hdr, 0x0000, 4);
+       ea_writebuf(sc, hdr, bufstart, 4);
 
        return len;
 }
@@ -1107,7 +1113,7 @@
 
                /* Tx next packet */
 
-               eatxpacket(sc);
+               ea_txpacket(sc);
        }
 }
 
@@ -1195,9 +1201,6 @@
                        log(LOG_ERR,
                            "%s: rx packet size error at %04x (len=%d)\n",
                            device_xname(&sc->sc_dev), addr, len);
-                       sc->sc_config2 |= SEEQ_CFG2_OUTPUT;
-                       SEEQ_WRITE16(sc, iot, ioh, SEEQ_CONFIG2,
-                                         sc->sc_config2);
                        ea_init(ifp);
                        return;
                }